Suchergebnisse

Este artículo contiene 2 páginas. ; CM-L received support from German Research Foundation (DFG: ME5498/3-1 and ME5498/2-1). NC received funding from the European UnionŁs Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No.839709. AL was supported by the Government of Catalonia and the European Commission through the program Beatriu de Pinós (BP-2018-00082). ; Peer reviewed

Este artículo contiene 13 páginas, 4 tablas, 6 figuras. ; Riparian trees can regulate streamflow dynamics and water budgets by taking up large amounts of water from both soil and groundwater compartments. However, their role has not been fully recognized in the hydrologic literature and the catchment modeling community. In this study, we explored the influence of riparian evapotranspiration (ET) on streamflow by simulating daily stream water exports from three nested Mediterranean catchments, both including and excluding the riparian compartment in the structure of the PERSiST (Precipitation, Evapotranspiration and Runoff Simulator for Solute Transport) rainfall–runoff model. The model goodness of fit for the calibration period (September 2010–August 2012) significantly improved with the inclusion of the riparian compartment, especially during the vegetative period, when according to our simulations, the riparian zone significantly reduced the overestimation of mean daily streamflow (from 53% to 27 %). At the catchment scale, simulated riparian ET accounted for 5.5% to 8.4% of annual water depletions over a 20-year reference period (1981–2000), and its contribution was especially noticeable during summer (from 8%to 26 %). Simulations considering climate change scenarios suggest large increases in riparian ET during the dormant period (from 19% to 46 %) but only small increases (from 1% to 2 %) in its contribution to annual water budgets. Overall, our results highlight that a good assessment of riparian ET is essential for understanding catchment hydrology and streamflow dynamics in Mediterranean regions. Thus, the inclusion of the riparian compartment in hydrological models is strongly recommended in order to establish proper management strategies in water-limited regions. ; Financial support was provided by the Spanish Government through projects MONTES-Consolider (CSD2008- 00040-MONTES), MEDFORESTREAM (CGL2011-30590), and MEDSOUL (CGL2014-59977-C3-2). Anna Lupon was supported by a Kempe Foundation stipend (Sweden). José L. J. Ledesma was funded by the Swedish Research Council (Svenska Forskningsrådet Formas, grant/award number 2015-1518). Susana Bernal's work was funded by European Social Funds (FSE) and the NICUS (CGL-2014-55234-JIN) project. ; Peer reviewed

17 páginas, 6 figuras, 4 tablas. ; Future changes in climate may affect soil nitrogen (N) transformations, and consequently, plant nutrition and N losses from terrestrial to stream ecosystems. We investigated the response of soil N cycling to changes in soil moisture, soil temperature, and precipitation across three Mediterranean forest types (evergreen oak, beech, and riparian) by fusing a simple process-based model (which included climate modifiers for key soil N processes) with measurements of soil organic N content, mineralization, nitrification, and concentration of ammonium and nitrate. The model describes sources (atmospheric deposition and net N mineralization) and sinks (plant uptake and hydrological losses) of inorganic N from and to the 0–10 cm soil pool as well as net nitrification. For the three forest types, the model successfully recreated the magnitude and temporal pattern of soil N processes and N concentrations (Nash-Sutcliffe coefficient = 0.49–0.96). Changes in soil water availability drove net N mineralization and net nitrification at the oak and beech forests, while temperature and precipitation were the strongest climatic factors for riparian soil N processes. In most cases, net N mineralization and net nitrification showed a different sensitivity to climatic drivers (temperature, soil moisture, and precipitation). Our model suggests that future climate change may have a minimal effect on the soil N cycle of these forests (<10% change in mean annual rates) because positive warming and negative drying effects on the soil N cycle may counterbalance each other. ; Financial support was provided by the Spanish Government through the projects MONTES-Consolider (CSD2008-00040-MONTES) and MEDFORESTREAM (CGL2011-30590). ; Peer reviewed

Monitoring nutrient concentrations at fine-scale temporal resolution contributes to a better understanding of nutrient cycling in stream ecosystems. However, the mechanisms underlying fine-scale nutrient dynamics and its implications for budget catchment fluxes are still poorly understood. To gain understanding on patterns and controls of fine-scale stream nitrogen (N) 18 dynamics and to assess how they affect hydrological N fluxes, we explored diel variation in stream nitrate (NO3-) concentration along a headwater stream with increasing riparian area and channel width. At the down-stream site, the highest day-night variations occurred in early-spring when stream NO3- concentrations were 13% higher at night than during day time. Such day-night variations were strongly related to daily light inputs (R2=0.74) and gross primary production (GPP) (R2=0.74), and they showed an excellent fit with day-night NO3- variations predicted from GPP (R2=0.85). These results suggest that diel fluctuations in stream NO3- concentration were mainly driven by photoautotrophic N uptake. Terrestrial influences were discarded because no simultaneous diel variations in stream discharge, riparian groundwater level, or riparian solute concentration were observed. In contrast to the down-stream site, no diel variations in NO3- concentration occurred at the up-stream site likely because water temperature was colder (10 vs. 12 ºC) and light availability was lower (4 vs. 9 mol m-2 d-1). Although daily GPP was between 10-100 folds lower than daily respiration, photoautotrophic N uptake contributed to a 10% reduction in spring NO3- loads at the down-stream site. Our study clearly shows that the activity of photoautotrophs can substantially change over time and along the stream continuum in response to key environmental drivers such as light and temperature, and further that its capacity to regulate diel and seasonal N fluxes can be important even in low productivity streams. ; Financial supported was provided by the Spanish Government through the projects MONTES-Consolider (CSD2008- 00040-MONTES) and MEDFORESTREAM (CGL2011-30590). ; Peer reviewed

Contiene 6 figuras, 3 tablas ; Riparian evapotranspiration (ET) can influence stream hydrology at catchment scale by promoting the net loss of water from the stream towards the riparian zone (i.e., stream hydrological retention). However, the consequences of stream hydrological retention on nitrogen dynamics are not well understood. To fill this gap of knowledge, we investigated changes in riparian ET, stream discharge, and nutrient chemistry in two contiguous reaches (headwater and valley) with contrasted riparian forest size in a small forested Mediterranean catchment. Additionally, riparian groundwater level (hgw) was measured at the valley reach. The temporal pattern of riparian ET was similar between reaches, was positively correlated with hgw (ρ = 0.60), and negatively correlated with net riparian groundwater inputs (ρ < -0.55). During the vegetative period, stream hydrological retention occurred only at the valley reach (59% of the time), and was accompanied by in-stream nitrate release and ammonium uptake. During the dormant period, when the stream gained water from riparian groundwater, results showed small influences of riparian ET on stream hydrology and nitrogen concentrations. Despite being a small component of annual water budgets (4.5%), our results highlight that riparian ET drives stream and groundwater hydrology in this Mediterranean catchment and, furthermore, question the potential of the riparian zone as a natural filter of nitrogen loads. ; Financial supported was provided by the Spanish Government through the projects MONTES-Consolider (CSD2008-00040-MONTES), MEDFORESTREAM (CGL2011-30590), and MEDSOUL (CGL2014-59977-C3-2). AL was supported by a FPU PhD fellowship from the Spanish Ministry of Education and Science (AP-2009-3711) and the MEDSOUL project. SB work was funded by the Spanish Research Council (JAE-DOC027), the Spanish CICT (Juan de la Cierva contract JCI-2008-177), European Social Funds (FSE), and the MEDFORESTREAM and NICUS (CGL-2014-55234-JIN) projects. SP was supported by a FPI PhD fellowship from the Spanish Ministry of Economy and Competitiveness (BES-2012-054572). ; Peer reviewed

Este artículo contiene 14 páginas, 5 figuras, 4 tablas. ; The capacity of headwater streams to transform and retain organic matter and nutrients during base flow conditions has been largely demonstrated in the literature. Yet, most solute exporting occurs during storms, and thus, it becomes essential to understand the role of in-stream processes in regulating solute concentrations and exports during storm flow conditions. In this study, we explored patterns of solute supply, solute demand, and resulting in-stream solute retention for a number of individual storms from two Mediterranean streams (intermittent and perennial) that together encompassed a wide range of hydrological conditions. Our results indicate that more than 70% of the individual storms were chemodynamic (i.e., solute concentrations either increased or decreased with increasing discharge) at the two sites, for both dissolved organic carbon (DOC) and nitrate (NO−3). At the perennial stream, DOC and NO−3 concentrations did not show any clear pattern of storm response during both dry and wet periods, though deviations from chemostasis were generally larger for those events showing higher concentrations during storm flow. At the intermittent stream, DOC and NO−3 showed positive divergences from chemostasis during the wet period. In this site, DOC showed no clear pattern of storm response during the dry period, while many storms showed low NO−3 concentrations compared to chemostasis, suggesting either limited NO−3 sources or in-stream retention. At the two streams, in-stream biogeochemical demand during individual storms was either similar or higher than during base flow conditions for both DOC and NO−3. In-stream NO−3 demand resulted in substantial whole-reach retention during storms (up to 40%), indicating that in-stream biogeochemical processes substantially reduced downstream flux of terrestrial NO−3 inputs during storm events. Conversely, whole-reach DOC retention was relatively low (<10%), suggesting little ability to regulate DOC export and an energy subsidy to downstream ecosystems during storms. This study indicates that in-stream biogeochemical demand during storms can counterbalance solute supply to some extent and stresses the importance of considering the potential role of in-stream processes in shaping stream solute export during storms. ; The work of SB was supported by the Spanish Government through the projects NICUS (CGL-2014-55234-JIN), CANTERA (RTI2018-094521-B-100) and a Ramon y Cajal fellowship (RYC-2017-22643). The work of SB, SP, EM, and FS was supported by the project MED_SOUL (CGL-2014-59977). AL was supported by the Spanish Ministry of Economy, Industry, and Competitiveness with a Juan de la Cierva contract (FJCI- 2016-28416). ; Peer reviewed

Este artículo contiene 14 páginas, 5 figuras, 2 tablas. ; Wastewater treatment plant (WWTP) effluents alter water chemistry and in-stream nutrient uptake rates of receiving freshwaters, thus changing the magnitude and fate of the nutrients exported. In Mediterranean regions, the dilution capacity of receiving streams can vary strongly over time due to the seasonal occurrence of floods and droughts, causing temporal variability of nutrient uptake. We assessed the temporal patterns and the controlling factors of net nutrient uptake in an intermittent Mediterranean stream receiving WWTP effluent inputs. We compiled the longitudinal concentration profiles of ambient dissolved inorganic nitrogen (DIN) and soluble reactive phosphorus (SRP) along a 800 m reach on 47 sampling dates between 2001 and 2017, encompassing a wide range of hydrological conditions. We estimated net nutrient uptake in the receiving stream. In 72% of the dates, high rates of net ammonium uptake co-occurred with net releases of either nitrate or nitrite. This pattern suggests that the receiving stream has a high nitrification capacity. Conversely, 75% of the dates did not show any longitudinal pattern in SRP concentration, suggesting that uptake and release processes for this element were either counterbalanced or both occurred at very low rates. Finally, net ammonium uptake was low when the stream had a low dilution capacity (< 40%) and ammonium concentration was high. Overall, we demonstrate that consideration of the receiving stream's dilution capacity is imperative to the management of freshwaters to guarantee an adequate dilution of WWTP effluent inputs and avoid saturation of in-stream nutrient uptake capacity under low flow conditions in urban landscapes. ; Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was funded by the projects "EcoReactors" (PGC2018-101975-B C22), "CANTERA" (RTI2018- 094521-B-100) and "Fluvial P-removal" (PID2019-111803RB-I00) from I + D program of the Spanish Ministry of Science, Innovation, and Universities. AL was supported by the program Beatriu de Pinós (BP-2018–00082) from the Government of Catalonia and the European Commission. JLJL was supported by a Marie Skłodowska-Curie Individual Fellowship (H2020-MSCA-IF-2018, RIPARIONS ref: 834363). SB was supported by a Ramon y Cajal fellowship (RYC-2017–22643) from the Spanish Ministry of Science, Innovation, and Universities. ; Peer reviewed

Este artículo contiene 18 páginas, 1 tabla, 5 figuras. ; Conferences are ideal platforms for studying gender gaps in science because they are important cultural events that reflect barriers to women in academia. Here, we explored women's participation in ecology conferences by analyzing female representation, behavior, and personal experience at the 1st Meeting of the Iberian Society of Ecology (SIBECOL). The conference had 722 attendees, 576 contributions, and 27 scientific sessions. The gender of attendees and presenters was balanced (48/52% women/men), yet only 29% of the contributions had a woman as last author. Moreover, men presented most of the keynote talks (67%) and convened most of the sessions. Our results also showed that only 32% of the questions were asked by women, yet the number of questions raised by women increased when the speaker or the convener was a woman. Finally, the post-conference survey revealed that attendees had a good experience and did not perceive the event as a threatening context for women. Yet, differences in the responses between genders suggest that women tended to have a worse experience than their male counterparts. Although our results showed clear gender biases, most of the participants of the conference failed to detect it. Overall, we highlight the challenge of increasing women's scientific leadership, visibility and interaction in scientific conferences and we suggest several recommendations for creating inclusive meetings, thereby promoting equal opportunities for all participants. ; AL was supported by the Government of Catalonia and the the European Social Fund (ESF) through the program Beatriu de Pino´s (BP-2018- 00082). PR-L was supported by a Margalida Comas postdoctoral contract (PD/031/2018), funded by the Government of the Balearic Islands and the ESF. AA-R was supported by a Humboldt Research Fellowship. MB was supported by the Spanish Government through the project Alkaldia (PID2019-111137GB-C21). SB was supported by a Ramon y Cajal fellowship from the Spanish Government and AEI/FEDER UE (RYC-2017- 22643). AGB was supported by a Marie Sklodowska-Curie (MSCA) Individual Fellowship (H2020-MSCA-IF-2016; project-749645). NC was funded by the European Union's Horizon 2020 research and innovation programme under the MSCA grant agreement No.839709. MJF was supported by the Portuguese Foundation of Science and Technology (FCT) through MARE strategic project (UIDB/04292/2020) and Norma Transito´ria. AGO was supported by the CESAM and FCT/MCTES (UIDP/50017/2020 + UIDB/50017/ 2020). CG-C was supported by the Spanish Government through a Juan de la Cierva – Incoporacio´n contract (IJC2018-036642-I). FL had a doctoral grant funded by FCT (PD/BD/52598/ 2014). GO was supported by the German Federal Ministry of Education and Research within the Collaborative Project"Bridging in Biodiversity Science – BIBS"(01LC1501A-H). SP was supported by a postdoctoral fellowship MSCA Seal of Excellence of the Research Foundation – Flanders (12ZZS21N). ; Peer reviewed

Coordinated distributed experiments (CDEs) enable the study of large-scale ecological patterns in geographically dispersed areas, while simultaneously providing broad academic and personal benefits for the participants. However, the effective involvement of early-career researchers (ECRs) presents major challenges. Here, we analyze the benefits and challenges of the first CDE exclusively led and conducted by ECRs (i.e. ECR-CDE), which sets a baseline for similar CDEs, and we provide recommendations for successful CDE execution. ECR-CDEs achieve most of the outcomes identified in conventional CDEs as well as extensive benefits for the young cohort of researchers, including: (i) receiving scientific credit, (ii) peer-training in new concepts and methods, (iii) developing leadership and communication skills, (iv) promoting a peer network among ECRs, and (v) building on individual engagement and independence. We also discuss the challenges of ECR-CDEs, which are mainly derived from the lack of independence and instability of the participants, and we suggest mechanisms to address them, such as resource re-allocation and communication strategies. We conclude that ECR-CDEs can be a relevant tool to empower ECRs across disciplines by fostering their training, networking and personal well-being ; The authors were supported by the following founding: NC the support of the Beatriu de Pinós postdoctoral program of the Government of Catalonia's Secretariat for Universities and Research of the Ministry of Economy and Knowledge (BP2016- 00215), EE by a predoctoral grant from the Basque Government 2014-2017), AB by a Generalitat de Catalunya—Beatriu de Pinós (BP-00385-2016), AMG-F by a predoctoral research grant (BES-2013-065770) from the Spanish Ministry of Economy and Competitiveness, MAr by a postdoctoral grant from the Basque Government, MIA by a Juan de la Cierva postdoctoral grant (FJCI-2015-26192), PR-L by a Margalida Comas postdoctoral contract (PD/031/2018) funded by the Government of the Balearic Islands and the ...

Coordinated distributed experiments (CDEs) enable the study of large-scale ecological patterns in geographically dispersed areas, while simultaneously providing broad academic and personal benefits for the participants. However, the effective involvement of early-career researchers (ECRs) presents major challenges. Here, we analyze the benefits and challenges of the first CDE exclusively led and conducted by ECRs (i.e. ECR-CDE), which sets a baseline for similar CDEs, and we provide recommendations for successful CDE execution. ECR-CDEs achieve most of the outcomes identified in conventional CDEs as well as extensive benefits for the young cohort of researchers, including: (i) receiving scientific credit, (ii) peer-training in new concepts and methods, (iii) developing leadership and communication skills, (iv) promoting a peer network among ECRs, and (v) building on individual engagement and independence. We also discuss the challenges of ECR-CDEs, which are mainly derived from the lack of independence and instability of the participants, and we suggest mechanisms to address them, such as resource re-allocation and communication strategies. We conclude that ECR-CDEs can be a relevant tool to empower ECRs across disciplines by fostering their training, networking and personal well-being. ; The authors were supported by the following founding: NC the support of the Beatriu de Pinós postdoctoral program of the Government of Catalonia's Secretariat for Universities and Research of the Ministry of Economy and Knowledge (BP2016-00215), EE by a predoctoral grant from the Basque Government (2014-2017), AB by a Generalitat de Catalunya—Beatriu de Pinós (BP-00385-2016), AMG-F by a predoctoral research grant (BES-2013-065770) from the Spanish Ministry of Economy and Competitiveness, MAr by a postdoctoral grant from the Basque Government, MIA by a Juan de la Cierva postdoctoral grant (FJCI-2015-26192), PR-L by a Margalida Comas postdoctoral contract (PD/031/2018) funded by the Government of the Balearic Islands and the European Social Fund, AP by a Ramón Areces Foundation Postdoctoral Scholarship, and AL by a Kempe Foundation stipend. DOMIPEX project was founded by the First Call of Collaborative Projects among Young Researchers of the Iberian Association of Limnology (AIL; 2013-2015). ; Peer reviewed

Este artículo contiene 7 páginas, 1 tabla, 3 figuras. ; Coordinated distributed experiments (CDEs) enable the study of large-scale ecological patterns in geographically dispersed areas, while simultaneously providing broad academic and personal benefits for the participants. However, the effective involvement of early-career researchers (ECRs) presents major challenges. Here, we analyze the benefits and challenges of the first CDE exclusively led and conducted by ECRs (i.e. ECR-CDE), which sets a baseline for similar CDEs, and we provide recommendations for successful CDE execution. ECR-CDEs achieve most of the outcomes identified in conventional CDEs as well as extensive benefits for the young cohort of researchers, including: (i) receiving scientific credit, (ii) peer-training in new concepts and methods, (iii) developing leadership and communication skills, (iv) promoting a peer network among ECRs, and (v) building on individual engagement and independence. We also discuss the challenges of ECR-CDEs, which are mainly derived from the lack of independence and instability of the participants, and we suggest mechanisms to address them, such as resource re-allocation and communication strategies. We conclude that ECR-CDEs can be a relevant tool to empower ECRs across disciplines by fostering their training, networking and personal well-being. ; The authors were supported by the following founding: NC the support of the Beatriu de Pinós postdoctoral program of the Government of Catalonia's Secretariat for Universities and Research of the Ministry of Economy and Knowledge (BP2016- 00215), EE by a predoctoral grant from the Basque Government (2014-2017), AB by a Generalitat de Catalunya—Beatriu de Pinós (BP-00385-2016), AMG-F by a predoctoral research grant (BES-2013-065770) from the Spanish Ministry of Economy and Competitiveness, MAr by a postdoctoral grant from the Basque Government, MIA by a Juan de la Cierva postdoctoral grant (FJCI-2015-26192), PR-L by a Margalida Comas postdoctoral contract (PD/031/2018) funded by the Government of the Balearic Islands and the European Social Fund, AP by a Ramón Areces Foundation Postdoctoral Scholarship, and AL by a Kempe Foundation stipend. DOMIPEX project was founded by the First Call of Collaborative Projects among Young Researchers of the Iberian Association of Limnology (AIL; 2013-2015). ; Peer reviewed